[Nix-dev] Re: Building an old GHC for a new Cabal...

[Marc Weber]

Excerpts from Yury G. Kudryashov's message of Wed May 12 23:38:04 +0200 2010:
> Marc Weber wrote:
> 
> >>   I do have GHC 6.10 still installed; but why does it not build
> >>   against the new GHC?
> > 
> > Because of a design decision Andres Loeh once made:
> > 
> > try cat `which ghc`. You'll see that ghc finds the packages containing
> > ghc libraries by iterating over $PATH.
> Marc, did you see the command in the original message?

No. I missed it cause it looked like a log line. Thank you for pointing
this out.

In any case using a collection should fix the trouble once and forall
(?) because packages are installed by attr path rather than by name.
I always install by attr path.
http://wiki.nixos.org/wiki/Howto_keep_multiple_packages_up_to_date_at_once

Marc Weber